Orthodontic appliances in the oral cavity may cause problems such as white spot lesions, dental plaque, periodontal disease and root resorption. The aim of this study was to investigate the association between orthodontic treatment and oral health parameters including visible dental plaque, gingival recession and white spot lesions (WSLs). A total of 170 patients (86 females, 84 males) were randomly selected to determine visible dental plaque, gingival recession and white spot lesions by using pre-treatment and post-treatment oral photographs. Except of previously extracted teeth, maxillary and mandibular incisors, canine, 1st and 2nd premolars and 1st molar were evaluated. There was a significant difference between the T0 (before treatment) and T1 (after treatment) groups in visible plaque (P< 0.001). The distribution of gingival recession frequencies according to Miller classification before treatment did not differ from the after treatment (P=.082). A statistically significant increase in the severity of WSL was detected between the two time points (P< 0.001). Males have been shown to have higher WSL incidence after treatment. In conclusion, the present study showed that visible dental plaque and white spot lesions significant increase after orthodontic treatment. Considering the relationship between oral health and orthodontic treatment, clinicians and patients should know the risks and take precautions.